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Rare case of squamous cell carcinoma of buccal mucosa metastasizing to
interventricular septum in a young adult detected by 18F-FDG PET-CT
Department of Nuclear Medicine & PET/CT, Amrita Institute of Medical Sciences,
Cochin, Kerala, India
Case Report
GS Shagos, S Padma, P Shanmuga Sundaram, Anshu Tewari
(Received 6 August 2013, Revised 12 December 2013, Accepted 14 December 2013)
ABSTRACT
Metastatic tumors to the heart unlike primary cardiac tumors are not rare. Despite its frequency, cardiac metastasis is
commonly detected only during autopsy as the symptoms of disseminated metastasis prevail over symptoms caused by
cardiac metastasis and hence is overlooked most of the time. Tumors more commonly found metastasizing to the heart are
malignancies of lung, breast, esophagus, lymphoma, leukemia, and malignant melanoma. Head and neck malignancies have
a lower incidence of distant metastasis when compared to other malignancies and it rarely causes cardiac metastasis. Here
we report the case of a 32 year old Indian male with squamous cell carcinoma of buccal mucosa who underwent surgery
followed by chemoradiation. Follow up, FDG PET-CT showed extensive lymphnodal, pulmonary & skeletal metastasis apart
from local recurrence in the tongue and floor of mouth. Another discrete foci of increased FDG uptake was noted in the
region of heart which corresponded to a hypodense foci in the interventricular septum in contrast enhanced CT raising the
possibility of cardiac metastasis. Subsequently, 2D echocardiogram with parasternal long axis view showed hyperdense
anterior septum with speckled appearance with a hyperechoic structure attached to the septum towards the right ventricular
side confirming metastatic deposit to the heart.
Key words: 18F-FDG PET-CT; Buccal mucosa; Cardiac metastasis; Interventricular septum
Iran J Nucl Med 2014;22(2):94-97
Published: June, 2014
http://irjnm.tums.ac.ir
Corresponding author: Dr Shagos GS, Department of Nuclear Medicine & PET/CT, Amrita Institute of Medical Sciences,
Cochin-6802041, Kerala, India. E-mail: [email protected]
Squamous cell carcinoma of buccal mucosa metastasizing to interventricular septum
Shagos et al.
INTRODUCTION
detected hypodense foci in the interventricular
septum.
Cardiac tumors can be primary or secondary. Primary
tumors of the heart are rare, the frequency being
approximately 0.02% in pooled autopsy series [1]
Metastatic tumors to the heart are at least 100 times
higher in frequency than primary tumors [2] and is
detected at autopsy in about 10-12 % of all patients
with malignancies [3, 4]. Majority of the primary
cardiac tumors are intracavitory whereas metastatic
tumors of the heart are seldom intracavitory and
hence most of them go unrecognized unless the
patient presents with overt clinical signs and
symptoms of cardiac arrhythmia, outflow tract
obstruction or heart failure. Although any malignant
neoplasm can metastasize to heart, the tumors that are
more prone to cause metastasis to the heart are
carcinomas of the lung, breast, esophagus,
lymphoma, leukemia, and malignant melanoma [5].
The postulated mechanisms by which cardiac
metastasis occur are [1] by direct extension, [2]
through the blood stream, [3] through lymphatic
system [4] and by intracavitory diffusion either
through inferior vena cava or the pulmonary veins
[6]. Metastasis to the heart can involve epicardium,
myocardium or endocardium, though the commonest
site to be affected is epicardium.
A 2D echocardiogram of the heart was done
subsequently. Parasternal long axis view in 2D echo
showed hyperdense anterior septum with speckled
appearance. A hyperechoic structure was seen
attached to the septum towards the right ventricular
side (Figure 3).
DISCUSSION
Cardiac metastasis is an incidental finding in majority
of the patients and is picked up during a radiological
investigation
following
chemotherapy
or
radiotherapy.
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Fig 1. whole-body maximum-intensity projection images showing
extensive metastasis in the form of multiple lymphnodal &
bilateral pulmonary metastasis.
Iran J Nucl Med 2014, Vol 22, No 2 (Serial No 42)
Here we present the case of a 32 year old Indian
male, a diagnosed case of squamous cell carcinoma
of buccal mucosa, who had undergone wide local
excision of the primary tumor along with partial
maxillectomy, segmental mandibulectomy, neck
dissection with radial forearm free flap
reconstruction.
Surgery
was
followed
by
chemoradiation. An FDG PET scan was requested to
know the extent of the disease as cervical
lymphnodal recurrence was suspected. Whole body
FDG-PET CT scan showed extensive metastasis in
the form of multiple lymphnodal, pulmonary &
skeletal metastasis apart from local recurrence in the
tongue and floor of mouth (Figure 1). Transaxial PET
images (Figure 2a) at the cardiac level showed
discrete foci of abnormal increased FDG uptake in
the region of heart (SUV Max 6.7). Abnormal foci of
increased FDG uptake can also be noted in bilateral
lung fields. Interestingly, the overall uptake in rest of
the myocardium is seen to be on the lower side.
Corresponding contrast enhanced CT images (Figure
2b) showed a hypodense foci in the interventricular
septum. Patchy and nodular areas of consolidation
can also be seen in the right lower lobe and in left
lower lobe. Fused PET-CT images (Figure 2c)
confirmed that the discrete intense FDG uptake in the
heart (SUV Max 6.4) corresponded to the CT
June, 2014
CASE REPORT
95
Squamous cell carcinoma of buccal mucosa metastasizing to interventricular septum
Shagos et al.
Fig 2c. Fused PET-CT transaxial images showing discrete foci of
increased FDG uptake to be corresponding to the hypodense foci
in the interventricular septum.
June, 2014
By the time metastasis to the heart has occurred, the
disease would most often have progressed
extensively to involve other organs and the
management is most often a palliative one. Overall,
the symptomatologies in such patients are
predominantly those related to other organ
involvement rather than related to cardiac
involvement. Diagnosis of intracardiac metastasis is
usually made during post mortem examination unless
the patient presents clinically with obvious clinical
signs of arrhythmias, heart failure, right ventricular
outflow tract obstruction or pericardial effusion.
Complete atrioventricular block, an uncommon
manifestation of metastatic cardiac tumor has been
reported previously where autopsy had revealed
metastatic involvement of the heart limited to
interventricular septum. Transthoracic ultrasound due
to its easy availability is the most common imaging
method used to detect cardiac metastasis. Contrast
MRI, based on varying signal intensities in T1 and
T2 weighted images has been proved by many
studies as a very effective tool in differentiating
between a cardiac thrombus and a cardiac tumor. 2D
echocardiography with its easy availability and cost
effectiveness has high sensitivity for evaluation of
cardiac masses and has made detection of cardiac
metastasis much simpler.
Review of the literature shows that cardiac metastasis
predominantly occurs during the sixth and seventh
decade of life following the overall age distribution
of malignant diseases [1]. Nowadays with the
widespread availability of FDG-PET imaging
facilities in most of the countries, many cases of
cardiac metastasis are being picked up during whole
body PET imaging. Rare case of an FDG-PET scan
helping to pick up a tumor in the right ventricle and
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Fig 2b. Transaxial CECT images at the cardiac level showing a
discrete hypodense foci in the interventricular septum. Patchy and
nodular areas of consolidation can also be seen in the right lower
lobe and in left lower lobe.
Fig 3. Parasternal long axis view in 2D echo showed hyperdense
anterior septum with speckled appearance. A hyperechoic structure
was seen attached to the septum towards the right ventricular side.
Iran J Nucl Med 2014, Vol 22, No 2 (Serial No 42)
Fig 2a.Transaxial PET images at the cardiac level showing a
discrete foci of increased FDG uptake (SUV Max 6.4) in the
region of heart. Multiple foci of abnormally increased FDG uptake
can also be noted in bilateral lung fields. Overall myocardial FDG
uptake is seen to be on the lower side.
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Squamous cell carcinoma of buccal mucosa metastasizing to interventricular septum
Shagos et al.
Reynen K. Frequency of primary tumors of the heart.
Am J Cardiol. 1996 Jan 1;77(1):107.
2.
Burke A, Virmani R. Tumors of the cardiovascular
system. In: Atlas of tumor pathology, 3rd Series,
Fascicle 16. Washington, DC: Armed Forces Institute of
Pathology; 1996.
3.
Abraham KP, Reddy V, Gattuso P. Neoplasms
metastatic to the heart: review of 3314 consecutive
autopsies. Am J Cardiovasc Pathol. 1990;3(3):195-8.
4.
Klatt EC, Heitz DR. Cardiac metastases. Cancer. 1990
Mar 15;65(6):1456-9.
5.
Bisel HF, Wroblewski F, Ladue JS. Incidence and
clinical manifestations of cardiac metastases. J Am Med
Assoc. 1953 Oct 24;153(8):712-5.
6.
Bussani R, De-Giorgio F, Abbate A, Silvestri F. Cardiac
metastases. J Clin Pathol. 2007 Jan;60(1):27-34.
7.
Shimotsu Y, Ishida Y, Fukuchi K, Hayashida K, Toba
M, Hamada S, Takamiya M, Satoh T, Nakanishi N,
Nishimura T. Fluorine-18-fluorodeoxyglucose PET
identification of cardiac metastasis arising from uterine
cervical carcinoma. J Nucl Med. 1998 Dec;39(12):20847.
8.
Kavanagh MM, Janjanin S, Prgomet D. Cardiac
metastases and a sudden death as a complication of
advanced stage of head and neck squamous cell
carcinoma. Coll Antropol. 2012 Nov;36 Suppl 2:19-21.
http://irjnm.tums.ac.ir
1.
June, 2014
REFERENCES
Iran J Nucl Med 2014, Vol 22, No 2 (Serial No 42)
septum in a patient presenting with cardiac
arrhythmia has been reported in the literature [7].
Even though any malignant tumor can metastasize to
the heart, reports of head and neck malignancies
metastasizing to the heart are rare. Aggressive
management of local malignancies
with
chemotherapy and radiotherapy and with availability
of better imaging modalities, more and more cases of
metastatic deposits to heart are being picked up
antemortem nowadays. Our patient, a 32 year old
male was initially treated with aggressive local
surgery followed by chemoradiation and
was
evaluated with an FDG-PET CT scan 07 months later
due to suspected local recurrence in the cervical
lymph node. Hypermetabolic foci was detected
corresponding to the clinically palpable cervical
lymph nodes. Whole body PET scan also revealed
multiple supra and infradiaphragmatic lymphnodal
and bilateral lung metastasis. Overall myocardial
uptake was lesser than the normal, but discrete foci of
increased FDG uptake was noted corresponding to
the interventricular septum in fused PET-CT images.
Subsequent 2D echocardiography revealed a
hyperechoic structure attached to the interventricular
septum which on clinical correlation with FDG-PET
CT images, was diagnostic of a metastatic foci in the
septum. Patient was quite asymptomatic with regards
to his cardiac status. Due to extensive distant
metastatic disease, relatives were not willing for any
aggressive management and he was referred for
palliative chemotherapy. So even though reported
literature speaks of cardiac metastasis as more
common in elderly age groups and that too as very
rare occurrence in head and neck malignancies [8],
our patient, a young male in his 4th decade is a
diagnosed case of squamous cell carcinoma of buccal
mucosa which had metastasized to the heart 07
months after his initial diagnosis.
97